Fixed Inductors

Part Number	Description / PDF	Quantity
B82422T1271J000 TDK EPCOS	FIXED IND 270NH 450MA 210 MOHM	0
B82473M1334K000 TDK EPCOS	FIXED IND 330UH 400MA 1.26 OHM	0
B78108S1684J000 TDK EPCOS	FIXED IND 680UH 150MA 10 OHM TH	11401
B82477P2224M000 TDK EPCOS	FIXED IND 220UH 1.15A 300 MOHM	533
B82422T1393K000 TDK EPCOS	FIXED IND 39UH 65MA 6.4 OHM SMD	0
B82476A1223M000 TDK EPCOS	FIXED IND 22UH 2.7A 50 MOHM SMD	622
B82498F3151G000 TDK EPCOS	FIXED IND 150NH 400MA 420 MOHM	0
B78148S1823J000 TDK EPCOS	FIXED IND 82UH 390MA 1.54 OHM TH	0
B82442H1122K000 TDK EPCOS	FIXED IND 1.2UH 2.35A 28 MOHM	0
B82111B0000C012 TDK EPCOS	FIXED IND 6UH 4A 17 MOHM TH	13
B82462G4332M000 TDK EPCOS	FIXED IND 3.3UH 2.3A 31 MOHM SMD	10877
B82422T1271K000 TDK EPCOS	FIXED IND 270NH 450MA 210 MOHM	0
B82498F3820J001 TDK EPCOS	FIXED IND 82NH 500MA 190 MOHM	696
B82559B5332A019 TDK EPCOS	FIXED IND 3.3UH 25.1A 2.25 MOHM	360
B78108S1683J000 TDK EPCOS	FIXED IND 68UH 410MA 1.35 OHM TH	8480
B82442A1222K000 TDK EPCOS	FIXED IND 2.2UH 1.3A 48 MOHM SMD	789
B82559B0303A016 TDK EPCOS	FIXED IND 30UH 8.5A 15.4 MOHM	328
B78148S1334J009 TDK EPCOS	FIXED IND 330UH 190MA 6.4 OHM TH	0
B82475M1104K000 TDK EPCOS	FIXED IND 100UH 970MA 350 MOHM	0
B82496C3129A000 TDK EPCOS	FIXED IND 1.2NH 1.8A 25 MOHM SMD	3301

Fixed Inductors

1. Overview

Fixed inductors are passive electronic components designed to store energy in magnetic fields when electrical current flows through them. Unlike variable inductors, their inductance values remain constant during operation. These components play critical roles in filtering, signal processing, energy storage, and electromagnetic interference (EMI) suppression across modern electronics, including power supplies, communication systems, and automotive electronics.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Wirewound Inductors	High precision, high current handling, low resistance	Power supplies, DC-DC converters
Chip Inductors	Compact SMD package, stable performance at high frequencies	Mobile devices, RF circuits
Ferrite Bead Inductors	Effective high-frequency noise suppression	EMI filtering in digital circuits
Thin-Film Inductors	Ultra-compact, high Q-factor, tight tolerance	5G communication modules, IoT devices

3. Structure and Composition

Typical fixed inductors consist of:

Magnetic Core: Made from ferrite, powdered iron, or composite materials to concentrate magnetic flux
Coil Structure: Copper wire wound around the core (enamelled or silver-plated)
Encapsulation: Molded resin or ceramic coating for mechanical protection and insulation
Terminations: Solder-coated ends for PCB mounting (for SMD types) or leaded connections

4. Key Technical Specifications

Parameter	Description	Importance
Inductance (L)	Measured in henrys (H), determines energy storage capacity	Defines filtering/energy storage performance
Rated Current (I_rated)	Maximum DC current before saturation	Prevents core saturation and failure
DC Resistance (DCR)	Resistance of coil windings	Affects efficiency and thermal performance
Self-Resonant Frequency (SRF)	Frequency where inductor behaves as capacitor	Limits effective operating frequency range
Q Factor	Quality factor indicating efficiency	Higher Q = lower energy losses

5. Application Fields

Consumer Electronics: Smartphones, laptops, LED drivers
Industrial Equipment: Motor drives, power inverters
Automotive Systems: ECU modules, EV battery management
Telecom Infrastructure: Base station filters, optical transceivers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Murata	LQH3NPN100M	10 H, 1.2A, 1.8 1.4mm chip inductor
TDK	MLZ2012A100T	100MHz SRF, 1.0 1.25mm for RF circuits
Vishay	IHLP2525CZER1R0M	1 H, 12A, composite construction
Coilcraft	0402DC-103J	10 H, 5% tolerance, ultra-low profile

7. Selection Guidelines

Key considerations during selection:

Calculate required inductance based on switching frequency and ripple current
Verify rated current exceeds maximum operating current by 20-30%
Select SRF higher than circuit operating frequency
Consider package size vs. thermal dissipation requirements
For EMI suppression: Choose ferrite beads with impedance curves matching target frequencies

8. Industry Trends

Current development trends include:

Miniaturization: Sub-0.5mm size inductors for wearable devices
High-Frequency Operation: Components supporting >10GHz 5G applications
Integrated Solutions: Combined inductor-filter modules
Material Innovation: Nanocrystalline cores for higher saturation flux
Automotive Focus: AEC-Q qualified parts for EV/HEV systems